Fix multiple code quality and security issues

app/build.gradle

@@ -5,11 +5,6 @@ plugins {
 android {
     namespace 'oyvindbs.zotshelf'
 
-    testOptions {
-        unitTests.all {
-            enabled = false
-        }
-    } 
     compileSdk 35
 
     defaultConfig {
@@ -25,12 +20,6 @@ android {
         buildConfigField "String", "ZOTERO_OAUTH_CLIENT_SECRET", "\"${System.getenv('ZOTERO_OAUTH_CLIENT_SECRET') ?: 'YOUR_CLIENT_SECRET_HERE'}\""
     }
 
-    testOptions {
-        unitTests.all {
-            enabled = false
-        }
-    }
-
     buildTypes {
         release {
             minifyEnabled false
@@ -48,8 +37,8 @@ android {
     }
 
     lint {
-        abortOnError false
-        checkReleaseBuilds false
+        abortOnError true
+        checkReleaseBuilds true
     }
 }
 

app/src/main/java/oyvindbs/zotshelf/CollectionFragment.java

@@ -1,5 +1,6 @@
 package oyvindbs.zotshelf;
 
+import android.app.Activity;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -146,9 +147,10 @@ private void loadCovers() {
                 new EpubCoverRepository.CoverRepositoryCallback() {
             @Override
             public void onCoversLoaded(List<EpubCoverItem> cachedCovers) {
-                if (getActivity() == null) return;
+                Activity activity = getActivity();
+                if (activity == null) return;
 
-                getActivity().runOnUiThread(() -> {
+                activity.runOnUiThread(() -> {
                     if (!cachedCovers.isEmpty()) {
                         updateUI(cachedCovers);
 
@@ -176,9 +178,10 @@ public void onCoversLoaded(List<EpubCoverItem> cachedCovers) {
 
             @Override
             public void onError(String message) {
-                if (getActivity() == null) return;
+                Activity activity = getActivity();
+                if (activity == null) return;
 
-                getActivity().runOnUiThread(() -> {
+                activity.runOnUiThread(() -> {
                     Log.e("CollectionFragment", "Error loading cached covers: " + message);
                     if (NetworkUtils.isNetworkAvailable(requireContext())) {
                         loadCoversFromApi();
@@ -245,9 +248,10 @@ public void onSuccess(List<ZoteroItem> zoteroItems) {
             public void onError(String errorMessage) {
                 Log.e("CollectionFragment", "=== API ERROR ===");
                 Log.e("CollectionFragment", "Error: " + errorMessage);
-                if (getActivity() == null) return;
+                Activity activity = getActivity();
+                if (activity == null) return;
 
-                getActivity().runOnUiThread(() -> {
+                activity.runOnUiThread(() -> {
                     progressBar.setVisibility(View.GONE);
                     swipeRefreshLayout.setRefreshing(false);
 
@@ -288,8 +292,9 @@ public void onSuccess(List<ZoteroItem> zoteroItems) {
                         zoteroItems.size() + " items from API");
                 processZoteroItemsForCache(zoteroItems);
 
-                if (getActivity() == null) return;
-                getActivity().runOnUiThread(() -> {
+                Activity activity = getActivity();
+                if (activity == null) return;
+                activity.runOnUiThread(() -> {
                     swipeRefreshLayout.setRefreshing(false);
                     Toast.makeText(requireContext(), "Library updated from Zotero",
                             Toast.LENGTH_SHORT).show();
@@ -299,9 +304,10 @@ public void onSuccess(List<ZoteroItem> zoteroItems) {
             @Override
             public void onError(String errorMessage) {
                 Log.e("CollectionFragment", "Background update error: " + errorMessage);
-                if (getActivity() == null) return;
+                Activity activity = getActivity();
+                if (activity == null) return;
 
-                getActivity().runOnUiThread(() -> {
+                activity.runOnUiThread(() -> {
                     swipeRefreshLayout.setRefreshing(false);
                 });
             }
@@ -343,9 +349,10 @@ private void loadCachedCovers() {
                 new EpubCoverRepository.CoverRepositoryCallback() {
             @Override
             public void onCoversLoaded(List<EpubCoverItem> covers) {
-                if (getActivity() == null) return;
+                Activity activity = getActivity();
+                if (activity == null) return;
 
-                getActivity().runOnUiThread(() -> {
+                activity.runOnUiThread(() -> {
                     if (covers.isEmpty()) {
                         showEmptyState("No cached covers found");
                     } else {
@@ -361,9 +368,10 @@ public void onCoversLoaded(List<EpubCoverItem> covers) {
 
             @Override
             public void onError(String message) {
-                if (getActivity() == null) return;
+                Activity activity = getActivity();
+                if (activity == null) return;
 
-                getActivity().runOnUiThread(() -> {
+                activity.runOnUiThread(() -> {
                     showEmptyState("Error loading cached covers: " + message);
                     swipeRefreshLayout.setRefreshing(false);
                 });
@@ -373,9 +381,10 @@ public void onError(String message) {
 
     private void processZoteroItems(List<ZoteroItem> zoteroItems) {
         if (zoteroItems.isEmpty()) {
-            if (getActivity() == null) return;
+            Activity activity = getActivity();
+            if (activity == null) return;
 
-            getActivity().runOnUiThread(() -> {
+            activity.runOnUiThread(() -> {
                 progressBar.setVisibility(View.GONE);
                 swipeRefreshLayout.setRefreshing(false);
 
@@ -497,9 +506,10 @@ public void onError(ZoteroItem item, String errorMessage) {
     }
 
     private void updateUI(final List<EpubCoverItem> newItems) {
-        if (getActivity() == null) return;
+        Activity activity = getActivity();
+        if (activity == null) return;
 
-        getActivity().runOnUiThread(() -> {
+        activity.runOnUiThread(() -> {
             coverItems.clear();
             coverItems.addAll(newItems);
 
@@ -577,9 +587,10 @@ public void updateDisplayMode() {
     }
 
     public void applySorting() {
-        if (getActivity() == null) return;
+        Activity activity = getActivity();
+        if (activity == null) return;
 
-        getActivity().runOnUiThread(() -> {
+        activity.runOnUiThread(() -> {
             if (!coverItems.isEmpty()) {
                 // Apply current sort mode
                 int sortMode = userPreferences.getSortMode();
@@ -601,9 +612,10 @@ public void applySorting() {
      * Show an error dialog
      */
     private void showErrorDialog(String title, String message) {
-        if (getActivity() == null) return;
+        Activity activity = getActivity();
+        if (activity == null) return;
 
-        AlertDialog.Builder builder = new AlertDialog.Builder(requireContext());
+        AlertDialog.Builder builder = new AlertDialog.Builder(activity);
         builder.setTitle(title);
         builder.setMessage(message);
         builder.setPositiveButton("OK", null);

app/src/main/java/oyvindbs/zotshelf/CoverGridAdapter.java

@@ -1,11 +1,15 @@
 package oyvindbs.zotshelf;
 
+import android.content.ClipData;
+import android.content.ClipboardManager;
 import android.content.Context;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.TextView;
+import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.recyclerview.widget.RecyclerView;
@@ -85,21 +89,57 @@ public void onBindViewHolder(@NonNull CoverViewHolder holder, int position) {
                 listener.onCoverClick(item);
             }
         });
+
+        // Set copy button click listener
+        holder.copyButton.setOnClickListener(v -> {
+            copyLinkToClipboard(item);
+        });
     }
 
     @Override
     public int getItemCount() {
         return coverItems.size();
     }
 
+    private void copyLinkToClipboard(EpubCoverItem item) {
+        UserPreferences userPreferences = new UserPreferences(context);
+        int linkType = userPreferences.getLinkType();
+        String link;
+        String linkLabel;
+
+        if (linkType == UserPreferences.LINK_TYPE_INTERNAL) {
+            // Internal Zotero link: zotero://select/library/items/{itemId}
+            link = "zotero://select/library/items/" + item.getId();
+            linkLabel = "Internal link";
+        } else {
+            // Web library link: https://www.zotero.org/{username}/items/{itemId}
+            String username = item.getZoteroUsername();
+            if (username == null || username.isEmpty()) {
+                username = userPreferences.getZoteroUsername();
+            }
+            link = "https://www.zotero.org/" + username + "/items/" + item.getId();
+            linkLabel = "Web link";
+        }
+
+        // Copy to clipboard
+        ClipboardManager clipboard = (ClipboardManager) context.getSystemService(Context.CLIPBOARD_SERVICE);
+        ClipData clip = ClipData.newPlainText(linkLabel, link);
+        clipboard.setPrimaryClip(clip);
+
+        // Show toast notification
+        Toast.makeText(context, linkLabel + " copied to clipboard", Toast.LENGTH_SHORT).show();
+    }
+
     static class CoverViewHolder extends RecyclerView.ViewHolder {
         ImageView coverImage;
         TextView titleText;
+        ImageButton copyButton;
 
         public CoverViewHolder(@NonNull View itemView) {
             super(itemView);
             coverImage = itemView.findViewById(R.id.imageCover);
             titleText = itemView.findViewById(R.id.textTitle);
+            copyButton = itemView.findViewById(R.id.buttonCopyLink);
         }
     }
 }

app/src/main/java/oyvindbs/zotshelf/SettingsActivity.java

@@ -29,6 +29,9 @@ public class SettingsActivity extends AppCompatActivity {
     private RadioButton radioTitleOnly;
     private RadioButton radioAuthorOnly;
     private RadioButton radioAuthorTitle;
+    private RadioGroup radioGroupLinkType;
+    private RadioButton radioLinkWeb;
+    private RadioButton radioLinkInternal;
     private Button buttonSave;
     private Button buttonOAuthLogin;
     private UserPreferences userPreferences;
@@ -58,6 +61,9 @@ protected void onCreate(Bundle savedInstanceState) {
         radioTitleOnly = findViewById(R.id.radioTitleOnly);
         radioAuthorOnly = findViewById(R.id.radioAuthorOnly);
         radioAuthorTitle = findViewById(R.id.radioAuthorTitle);
+        radioGroupLinkType = findViewById(R.id.radioGroupLinkType);
+        radioLinkWeb = findViewById(R.id.radioLinkWeb);
+        radioLinkInternal = findViewById(R.id.radioLinkInternal);
         buttonSave = findViewById(R.id.buttonSave);
         buttonOAuthLogin = findViewById(R.id.buttonOAuthLogin);
 
@@ -121,6 +127,14 @@ private void loadPreferences() {
                 radioTitleOnly.setChecked(true);
                 break;
         }
+
+        // Set the link type radio button
+        int linkType = userPreferences.getLinkType();
+        if (linkType == UserPreferences.LINK_TYPE_INTERNAL) {
+            radioLinkInternal.setChecked(true);
+        } else {
+            radioLinkWeb.setChecked(true);
+        }
     }
 
     private void savePreferences() {
@@ -166,6 +180,16 @@ private void savePreferences() {
         }
         userPreferences.setDisplayMode(displayMode);
 
+        // Save link type
+        int linkType;
+        int selectedLinkTypeId = radioGroupLinkType.getCheckedRadioButtonId();
+        if (selectedLinkTypeId == R.id.radioLinkInternal) {
+            linkType = UserPreferences.LINK_TYPE_INTERNAL;
+        } else {
+            linkType = UserPreferences.LINK_TYPE_WEB;
+        }
+        userPreferences.setLinkType(linkType);
+
         Toast.makeText(this, R.string.settings_saved, Toast.LENGTH_SHORT).show();
         finish();
     }

app/src/main/java/oyvindbs/zotshelf/UserPreferences.java

@@ -16,7 +16,8 @@ public class UserPreferences {
     private static final String KEY_SHOW_PDFS = "show_pdfs";
     private static final String KEY_BOOKS_ONLY = "books_only";
     private static final String KEY_SORT_MODE = "sort_mode";
-
+    private static final String KEY_LINK_TYPE = "link_type";
+
     // Display mode constants
     public static final int DISPLAY_TITLE_ONLY = 0;
     public static final int DISPLAY_AUTHOR_ONLY = 1;
@@ -25,7 +26,11 @@ public class UserPreferences {
     // Sort mode constants
     public static final int SORT_BY_TITLE = 0;
     public static final int SORT_BY_AUTHOR = 1;
-
+
+    // Link type constants
+    public static final int LINK_TYPE_WEB = 0;
+    public static final int LINK_TYPE_INTERNAL = 1;
+
     private final SharedPreferences preferences;
 
     public UserPreferences(Context context) {
@@ -130,6 +135,14 @@ public boolean hasAnyFileTypeEnabled() {
         return getShowEpubs() || getShowPdfs();
     }
 
+    public int getLinkType() {
+        return preferences.getInt(KEY_LINK_TYPE, LINK_TYPE_WEB); // Default to web link
+    }
+
+    public void setLinkType(int linkType) {
+        preferences.edit().putInt(KEY_LINK_TYPE, linkType).apply();
+    }
+
     public void clearAll() {
         preferences.edit().clear().apply();
     }